htop - an interactive process viewer
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Michael Witten ab3171d21d Process.{h,c}: Use integer types that are more portable
When building on a 32-bit system, the compiler warned that the
following line uses a constant whose value is the overflow result
of a compile-time computation:

  Process.c (line 109):   } else if (number < 10000 * ONE_M) {

Namely, this constant expression:

  10000 * ONE_M

was intended to produce the following value:

  10485760000

However, the result overflowed to produce:

   1895825408

The reason for this overflow is as follows:

  o The macros are expanded:

      10000 * (ONE_K * ONE_K)
      10000 * (1024L * 1024L)

  o The untyped constant expression "10000" is typed:

      10000U * (1024L * 1024L)

  o The parenthesized expression is evaluated:

      10000U * (1048576L)

  o The left operand ("10000U") is converted:

      10000L * (1048576L)

    Unbound by integer sizes, that last multiplication
    would produce the following value:

      10485760000

    However, on a 32-bit machine, where a long is 32 bits
    (really 31 bits when talking about positive numbers),
    the maximum value that can be computed is 2**31-1:

      2147483647

    Consequently, the computation overflows.

  o The compiler produces a long int value that is the
    the result of overflow (10485760000 % 2**31):

      1895825408L

    Actually, I think this overflow is implementation-defined,
    so it's not even a portable description of what happens.

The solution is to use a long long int (or, even better,
an unsigned long long int) type for the constant expression;
the C standard mandates a sufficiently large maximum value
for such types.

Hence, the following change is made to the bad line:

  -   } else if (number < 10000 * ONE_M) {
  +   } else if (number < 10000ULL * ONE_M) {

However, the whole line is now patently silly, because the
variable "number" is typed "unsigned long", and so it will
always be less than the constant expression (the compiler
will warn about this, too).

Hence, "number" must be typed "unsigned long long"; however,
this necessitates changing all of the string formats from
something like "%lu" to something like "%llu".

Et voila! This commit is born.

Then, for the sake of completeness, the declared types of the
constant-expression macros are updated:

  o ONE_K is made unsigned (a "UL" instead of "L")
  o ONE_T is computed by introducing "1ULL *"
  o Similar changes are made for ONE_DECIMAL_{K,T}

Also, a non-portable overflow-conversion to a signed value
has been replaced with a portable comparison:

  -   if ((long long) number == -1LL) {
  +   if (number == ULLONG_MAX) {

It might be worth reviewing the rest of the code for other
cases where overflows are not handled correctly; even at
runtime, it's often necessary to check for overflow unless
such behavior is expected (especially for signed integer
values, for which overflow has implementation-defined
behavior).
2020-09-29 15:47:52 +00:00
.github/workflows Make --enable-hwloc and --enable-linux-affinity mutual exclusive 2020-09-24 19:43:27 +02:00
darwin CPUMeter: add octuple-column CPU meters. 2020-09-28 14:35:35 +02:00
dragonflybsd CPUMeter: add octuple-column CPU meters. 2020-09-28 14:35:35 +02:00
freebsd CPUMeter: add octuple-column CPU meters. 2020-09-28 14:35:35 +02:00
linux Drop redundant declarations 2020-09-29 10:44:42 +02:00
openbsd CPUMeter: add octuple-column CPU meters. 2020-09-28 14:35:35 +02:00
scripts Add script to run htop under valgrind 2020-09-17 22:06:36 +02:00
solaris CPUMeter: add octuple-column CPU meters. 2020-09-28 14:35:35 +02:00
unsupported CPUMeter: add octuple-column CPU meters. 2020-09-28 14:35:35 +02:00
zfs Refactor __attribute__ usage 2020-09-18 12:28:40 +02:00
.editorconfig Add trim_trailing_whitespace to editorconfig 2019-10-31 11:39:57 -05:00
.gitignore Axe automated header generation. 2020-09-03 11:58:58 -05:00
.travis.yml Fail travis CI on compiler warnings 2020-09-18 12:28:40 +02:00
Action.c Drop redundant casts to the same type 2020-09-29 10:44:42 +02:00
Action.h Use strict function prototypes 2020-09-18 12:28:40 +02:00
Affinity.c Avoid checking of undefined macros 2020-09-18 12:28:40 +02:00
Affinity.h Make --enable-hwloc and --enable-linux-affinity mutual exclusive 2020-09-24 19:43:27 +02:00
AffinityPanel.c Do not drop qualifier in cast 2020-09-24 20:14:17 +02:00
AffinityPanel.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
AUTHORS Initial import. 2006-03-04 18:16:49 +00:00
autogen.sh autotools: enable warnings and cleanup 2020-09-17 21:45:11 +02:00
AvailableColumnsPanel.c Call character checking function with unsigned char 2020-09-17 22:03:24 +02:00
AvailableColumnsPanel.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
AvailableMetersPanel.c Drop redundant casts to the same type 2020-09-29 10:44:42 +02:00
AvailableMetersPanel.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
BatteryMeter.c Drop redundant return statements 2020-09-29 10:44:42 +02:00
BatteryMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
CategoriesPanel.c Call character checking function with unsigned char 2020-09-17 22:03:24 +02:00
CategoriesPanel.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
ChangeLog Bump version, changelog for minor htop-3.0.2 release 2020-09-15 09:43:36 +10:00
CheckItem.c Axe automated header generation. 2020-09-03 11:58:58 -05:00
CheckItem.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
ClockMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
ClockMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
ColorsPanel.c Axe automated header generation. 2020-09-03 11:58:58 -05:00
ColorsPanel.h Clean up some code duplication in the header files 2020-09-12 19:20:44 -03:00
ColumnsPanel.c Call character checking function with unsigned char 2020-09-17 22:03:24 +02:00
ColumnsPanel.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
CommandScreen.c command screen: fill current line when scanning 2020-09-29 10:11:28 +02:00
CommandScreen.h show selected command wrapped in a separate window 2020-09-24 19:22:25 +02:00
configure.ac Merge pull request #107 from cgzones/hwlock_linuxaffinity 2020-09-28 16:47:47 +10:00
CONTRIBUTING.md Updates to project URLs in docs and embedded in source code 2020-08-22 15:47:11 +10:00
COPYING Remove trailing whitespaces 2020-08-21 10:37:33 +02:00
CPUMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
CPUMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
CRT.c Mark noreturn functions 2020-09-18 12:28:40 +02:00
CRT.h Drop redundant declarations 2020-09-29 10:44:42 +02:00
DisplayOptionsPanel.c Do not drop qualifier in cast 2020-09-24 20:14:17 +02:00
DisplayOptionsPanel.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
EnvScreen.c Consolidate repeated macro definitions into one header 2020-09-09 16:56:04 +10:00
EnvScreen.h Remove superfluous 'extern's from function declarations. 2020-09-03 11:59:26 -05:00
FunctionBar.c Axe automated header generation. 2020-09-03 11:58:58 -05:00
FunctionBar.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
Hashtable.c Axe automated header generation. 2020-09-03 11:58:58 -05:00
Hashtable.h Remove superfluous 'extern's from function declarations. 2020-09-03 11:59:26 -05:00
Header.c Clean up some code duplication in the header files 2020-09-12 19:20:44 -03:00
Header.h Consolidate repeated macro definitions into one header 2020-09-09 16:56:04 +10:00
HostnameMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
HostnameMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
htop.1.in show selected command wrapped in a separate window 2020-09-24 19:22:25 +02:00
htop.c Avoid warning about unreachable break statement 2020-09-24 20:14:17 +02:00
htop.desktop Add danish translation to htop.desktop 2019-02-19 01:25:52 +01:00
htop.png Updated icon! 2014-04-09 14:47:58 -03:00
IncSet.c Call character checking function with unsigned char 2020-09-17 22:03:24 +02:00
IncSet.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
InfoScreen.c Drop redundant casts to the same type 2020-09-29 10:44:42 +02:00
InfoScreen.h Add format attribute 2020-09-18 12:28:40 +02:00
ListItem.c Do not drop qualifier in cast 2020-09-24 20:14:17 +02:00
ListItem.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
LoadAverageMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
LoadAverageMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
Macros.h Refactor __attribute__ usage 2020-09-18 12:28:40 +02:00
MainPanel.c Call character checking function with unsigned char 2020-09-17 22:03:24 +02:00
MainPanel.h Use strict function prototypes 2020-09-18 12:28:40 +02:00
Makefile.am show selected command wrapped in a separate window 2020-09-24 19:22:25 +02:00
MemoryMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
MemoryMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
Meter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
Meter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
MetersPanel.c Do not drop qualifier in cast 2020-09-24 20:14:17 +02:00
MetersPanel.h Free movingBar memory on exit 2020-09-17 22:04:11 +02:00
NEWS Remove trailing whitespaces 2020-08-21 10:37:33 +02:00
Object.c Axe automated header generation. 2020-09-03 11:58:58 -05:00
Object.h Consolidate repeated macro definitions into one header 2020-09-09 16:56:04 +10:00
OpenFilesScreen.c Check for fdopen failure in OpenFilesScreen_getProcessData 2020-09-17 21:43:53 +02:00
OpenFilesScreen.h Further, minor cleanups to headers post-MakeHeaders 2020-09-08 17:33:50 +10:00
Panel.c Call character checking function with unsigned char 2020-09-17 22:03:24 +02:00
Panel.h Drop unused variable 2020-09-18 12:22:18 +02:00
Process.c Process.{h,c}: Use integer types that are more portable 2020-09-29 15:47:52 +00:00
Process.h Process.{h,c}: Use integer types that are more portable 2020-09-29 15:47:52 +00:00
ProcessList.c Switch variable/field naming from WhiteList to MatchList 2020-09-09 19:38:15 +10:00
ProcessList.h Switch variable/field naming from WhiteList to MatchList 2020-09-09 19:38:15 +10:00
README Update creation date to 2004 (thanks rubyFeedback) 2020-09-17 09:47:28 +02:00
README.md Add README.md for Github 2014-02-03 09:11:39 -02:00
RichString.c Avoid checking of undefined macros 2020-09-18 12:28:40 +02:00
RichString.h Avoid checking of undefined macros 2020-09-18 12:28:40 +02:00
ScreenManager.c Do not drop qualifier in cast 2020-09-24 20:14:17 +02:00
ScreenManager.h Do not drop qualifier in cast 2020-09-24 20:14:17 +02:00
Settings.c Reorder check to avoid crash on invalid process field setting 2020-09-17 21:46:22 +02:00
Settings.h Revert the vim_mode setting for now, needs a rethink 2020-09-15 09:33:58 +10:00
SignalsPanel.c Axe automated header generation. 2020-09-03 11:58:58 -05:00
SignalsPanel.h Use strict function prototypes 2020-09-18 12:28:40 +02:00
StringUtils.c Drop redundant casts to the same type 2020-09-29 10:44:42 +02:00
StringUtils.h Remove superfluous 'extern's from function declarations. 2020-09-03 11:59:26 -05:00
SwapMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
SwapMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
TasksMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
TasksMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
test_spec.lua Remove trailing whitespaces 2020-08-21 10:37:33 +02:00
TESTPLAN Remove trailing whitespaces 2020-08-21 10:37:33 +02:00
TraceScreen.c Avoid hardcoding of buffer size 2020-09-17 21:43:05 +02:00
TraceScreen.h Remove superfluous 'extern's from function declarations. 2020-09-03 11:59:26 -05:00
UptimeMeter.c Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
UptimeMeter.h Covert Meter attributes to file-local constant arrays 2020-09-29 10:44:42 +02:00
UsersTable.c Axe automated header generation. 2020-09-03 11:58:58 -05:00
UsersTable.h Use strict function prototypes 2020-09-18 12:28:40 +02:00
Vector.c Drop redundant casts to the same type 2020-09-29 10:44:42 +02:00
Vector.h Clean up some code duplication in the header files 2020-09-12 19:20:44 -03:00
XAlloc.c Drop unused macros 2020-09-24 20:14:17 +02:00
XAlloc.h Mark noreturn functions 2020-09-18 12:28:40 +02:00

htop

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Introduction

htop is a cross-platform interactive process viewer.

htop allows scrolling the list of processes vertically and horizontally to see their full command lines and related information like memory and CPU consumption.

The information displayed is configurable through a graphical setup and can be sorted and filtered interactively.

Tasks related to processes (e.g. killing and renicing) can be done without entering their PIDs.

Running htop requires ncurses libraries (typically named libncursesw*).

For more information and details on how to contribute to htop visit htop.dev.

Build instructions

This program is distributed as a standard GNU autotools-based package.

Compiling htop requires the header files for ncurses (libncursesw*-dev). Install these and other required packages for C development from your package manager.

Then, when compiling from a release tarball, run:

./configure && make

Alternatively, for compiling sources downloaded from the Git repository (git clone or downloads from Github releases), install the header files for ncurses (libncursesw*-dev) and other required development packages from your distribution's package manager. Then run:

./autogen.sh && ./configure && make

By default make install will install into /usr/local, for changing the path use ./configure --prefix=/some/path.

See the manual page (man htop) or the on-line help ('F1' or 'h' inside htop) for a list of supported key commands.

Support

If you have trouble running htop please consult your Operating System / Linux distribution documentation for getting support and filing bugs.

Bugs, development feedback

We have a development mailing list. Feel free to subscribe for release announcements or asking questions on the development of htop.

You can also join our IRC channel #htop on freenode and talk to the developers there.

If you have found an issue with the source of htop, please check whether this has already been reported in our Github issue tracker. If not, please file a new issue describing the problem you have found, the location in the source code you are referring to and a possible fix.

History

htop was invented, developed and maintained by Hisham Muhammad from 2004 to 2019. His legacy repository has been archived to preserve the history.

In 2020 a team took over the development amicably and continues to maintain htop collaboratively.

License

GNU General Public License, version 2 (GPL-2.0)